Kotlin versus Java: Which is Better for Android App Development in 2025?

Mobile apps’ universe is expanding quickly. New apps come out every day with better experiences and clever capabilities.
Android app development sits at the core of this wave, Java vs Kotlin. Often caught wondering, developers ask: “Which one should I pick—Kotlin or Java?”
This is a reasonable query. Both are rather strong. Both have devoted supporters. Still, one would be more suited for your circumstances than the other.

We shall keep things basic on this blog. We will examine actual Java against Kotlin variations, discuss how each performs in actual use, and assist you in choosing which one fits your project most.
This book is for you whether your business runs an app-building agency, deals with Android app development companies, or you are a developer personally.

What is Kotlin vs Java?

First, let’s talk about what Kotlin and Java are.
Java is old, but it’s gold. It’s been around since the 1990s and was the first language that Android apps could work with. It works well, has lots of documentation, and has a big group of developers. It’s likely that a lot of the apps you use on your Android phone were made with Java.
Kotlin, on the other hand, is new and stylish. It came out in 2011, but it got more attention when Google made it an official language for developing Android in 2017. Kotlin is neat, short, and gets rid of a lot of extra code. Because of this, many current companies that make apps for Android now prefer it.
We can get started well if we know the difference between Kotlin and Java. Let’s look into this more.

Java vs Kotlin Performance: Which Is Faster?

Time is important. It depends on how you write your code a lot of the time when we talk about how fast Java or Kotlin is.
Because it’s easier to use, Java is sometimes faster. It starts up quickly and doesn’t use much memory. This is helpful if your app is big or deals with a lot of info.
But Kotlin shines in how smart it is. Writing logic and doing hard jobs is faster and easier with it. Kotlin can cut down on bugs and runtime errors, but it can take longer to build sometimes. This can indirectly speed up the app and make it easier to use.

Java and Kotlin are both fast, but there isn’t a clear winner. Java works well and is quick. Kotlin is clean and smart. This pick is best based on the type of app you are making.
Code Comparison Between Java and Kotlin

This is where things start to look real. Let’s compare some simple code written in Java and Kotlin.
This Java vs. Kotlin code comparison shows that Kotlin runs faster and is easier to read. It only takes a few lines to do the same thing. This makes teams work faster and lessens the chance of mistakes.
Kotlin is better if your app-building company wants to build quickly and with fewer bugs. But Java is still the best choice if you need standard structure and support for a long time.

Key Differences Between Java and Kotlin

When choosing a language for your app, it’s helpful to know the main differences between Java and Kotlin.
Some important things to know about Android Java vs. Kotlin:
Null Safety: Kotlin has null safety built in. Java doesn’t have that.
Kotlin’s syntax is short. J2EE has more words.

Extension Functions: You can add functions to classes that already exist in Kotlin. No, Java doesn’t.
Instead of coroutines, Kotlin’s asynchronous tasks work better.
Learning Curve: It’s easier to get started with Java. It takes time to learn Kotlin.
A lot of developers care about these changes between Java and Kotlin. Pick something that fits the size, speed, and goals of your job.

Which is better for an Android app: Kotlin or Java?
Kotlin is slowly becoming the language of choice for most current companies that make Android apps instead of Java. But why?
Kotlin speeds up the writing of code. Fewer lines of code mean fewer bugs. That means delivery will happen faster and with less testing. J2EE works well with it too. You can still use Kotlin code in a game that was written in Java.
Still, some app-building companies like Java because it has a large community of users who back it. You can count on it, and there are more Java workers out there.
Which android app java or kotlin to use relies on what you value more: speed or simplicity, tradition or new ideas.

Java vs. Kotlin for Making Android Apps: Real-World Examples

Take a look at how big businesses decide what to do.
Which is better for making Android apps: Kotlin or Java? Both have been used by big brands.
Python: A lot of LinkedIn, Netflix, and Spotify’s apps are still written in Python.

Kotlin: New features and changes are being planned for Kotlin by Pinterest, Uber, and Trello.
Why does it matter? It’s clear where the future is going if big companies use Kotlin. You might want to stick with what works, though, if the people on your team already know a lot about Java.
A lot of businesses use both in real life. If you want to make an Android game, you don’t always have to choose between Java and Kotlin. Often, you can use both.

Why company that makes Android apps choose Kotlin in 2025

It’s 2025, and technology changes very quickly. The goal of most companies that make Android apps is to make apps that are faster, better, and more reliable.
That’s why Kotlin is getting bigger. It cuts down on time to market and makes upkeep easy. Google is also always making the Kotlin tools in Android Studio better.

Java is still around. Java still works well with many apps that were made 5–10 years ago. It stays alive thanks to fixes and updates.
When it comes to making Android apps, the future may lie with Kotlin, but Java isn’t going away any time soon.

Last Thoughts: The Right Tool for the Job

To sum up, you don’t have to choose between Java and Kotlin when making Android apps. You need to find the right tool for your job and team.
Kotlin is more bug-free, faster, and has shorter code. Java is a good choice if you want a stable language with lot of community help.

The best companies that make Android apps know how to find this mix. They build strong, flexible, and useful mobile apps by using the best parts of both languages.
Before you decide which is better for Android (Java vs. Kotlin), you should think about what your app really needs.